8,175 research outputs found
Infrared testing of electronic components Final report, 5 Apr. 1965 - 5 Jun. 1966
Infrared radiation nondestructive test technique for electrical/electronic equipmen
The HATNet and HATSouth Exoplanet Surveys
The Hungarian-made Automated Telescope Network (HATNet) has been in operation
since 2003, with the key science goal being the discovery and accurate
characterization of transiting extrasolar planets (TEPs) around bright stars.
Using six small, 11\,cm\ aperture, fully automated telescopes in Arizona and
Hawaii, as of 2017 March, it has discovered and accurately characterized 67
such objects. The HATSouth network of telescopes has been in operation since
2009, using slightly larger, 18\,cm diameter optical tubes. It was the first
global network of telescopes using identical instrumentation. With three
premier sites spread out in longitude (Chile, Namibia, Australia), the HATSouth
network permits round-the-clock observations of a 128 square arcdegree swath of
the sky at any given time, weather permitting. As of this writing, HATSouth has
discovered 36 transiting exoplanets. Many of the altogether ~100 HAT and
HATSouth exoplanets were the first of their kind. They have been important
contributors to the rapidly developing field of exoplanets, motivating and
influencing observational techniques, theoretical studies, and also actively
shaping future instrumentation for the detection and characterization of such
objects.Comment: Invited review chapter, accepted for publication in "Handbook of
Exoplanets", edited by H.J. Deeg and J.A. Belmonte, Springer Reference Work
Enceladus: Cassini observations and implications for the search for life
Aims. The recent Cassini discovery of water vapor plumes ejected from the south pole of the Saturnian satellite, Enceladus, presents a unique window of opportunity for the detection of extant life in our solar system.
Methods. With its significant geothermal energy source propelling these plumes >80 km from the surface of the moon and the ensuing large temperature gradient with the surrounding environment, it is possible to have the weathering of rocks by liquid water at the rock/liquid interface. For the cases of the putatively detected salt-water oceans beneath the ice crusts of Europa and Callisto, an isolated subsurface ocean without photosynthesis or contact with an oxidizing atmosphere will approach chemical equilibrium and annihilate any ecosystems dependent on redox gradients unless there is a substantial alternative energy source. This thermodynamic tendency imposes severe constraints on any biota that is based on chemical energy. On Enceladus, the weathering of rocks by liquid water and any concomitant radioactive emissions are possible incipient conditions for life. If there is CO, CO2 and NH3 present in the spectra obtained from the plume, then this is possible evidence that amino acids could be formed at the rock/liquid interface of Enceladus. The combination of a hydrological cycle, chemical redox gradient and geochemical cycle give favorable conditions for life.
Results. We discuss the search for signatures of these species and organics in the Cassini UVIS spectra of the plume and implications for the possible detection of life
Conceptual mechanization studies for a horizon definition spacecraft attitude control subsystem, phase A, part II, 10 October 1966 - 29 May 1967
Attitude control subsystem for spin stabilized spacecraft for mapping earths infrared horizon radiance profiles in 15 micron carbon dioxide absorption ban
The last Gift of BeppoSAX: PDS Observations of the two Blazars 1ES 0507-040 and PKS 1229-021
Towards the end of the BeppoSAX mission, the only operated Narrow Field
Instrument was the PDS, which covers the energy range 13-300 keV. Two blazars,
1ES 0507-040 (z=0.304) and PKS 1229-021 (z= 1.045), suitably located in the sky
for BeppoSAX pointing, were observed for about 2 days each in Spring 2002 with
the PDS and detected up to 50 keV. 1ES0507-040 had been already observed by the
BeppoSAX NFIs at an earlier epoch for a much shorter time. We have re-analysed
those data as well, and identified a possible contamination problem in the PDS
spectrum. We present our recent PDS data on both sources, combined with the
previous BeppoSAX data and with non-simultaneous observations at other
frequencies. The derived Spectral Energy Distributions allow us to discuss the
origin of the high energy component.Comment: 4 pages, 6 figures, poster presented at the symposium: The Restless
High-Energy Universe, Amsterdam, May 200
Mammalian Cell Cytotoxicity Analysis of Soybean Rust Fungicides
The identification of soybean rust, caused by Phakopsora
pachyrhizi H. Sydow & Sydow, in the southern United
States in November 2004 (Schneider et al. 2005 ), in the
Midwest in 2006 (Hartman et al. 2007 ), and elsewhere has
increased the concerns of the impact of the pathogen on US
soybean production (Miles et al. 2007 ). The rapid spread of
P. pachyrhizi and its potential to cause severe yield losses
makes this among the most destructive foliar diseases of
soybean. Yield losses of 20%â60% were reported in Asia,
with losses of 80% reported from experimental plots in
Taiwan (Hartman et al. 1991 ). Soybean rust could have a
major impact on both total soybean production and production
costs in the US
Nonlinear modes for the Gross-Pitaevskii equation -- demonstrative computation approach
A method for the study of steady-state nonlinear modes for Gross-Pitaevskii
equation (GPE) is described. It is based on exact statement about coding of the
steady-state solutions of GPE which vanish as by reals. This
allows to fulfill {\it demonstrative computation} of nonlinear modes of GPE
i.e. the computation which allows to guarantee that {\it all} nonlinear modes
within a given range of parameters have been found. The method has been applied
to GPE with quadratic and double-well potential, for both, repulsive and
attractive nonlinearities. The bifurcation diagrams of nonlinear modes in these
cases are represented. The stability of these modes has been discussed.Comment: 21 pages, 6 figure
Optical and infrared photometry of the blazar PKS0537-441
We present a large collection of photometric data on the Blazar PKS 0537-441
in the VRIJHK bands taken in 2004-2009. At least three flare-like episodes with
months duration, and >3 mag amplitude are apparent. The spectral energy
distribution is consistent with a power law, and no indication of a thermal
component is found. We searched for short time scale variability, and an
interesting event was identified in the J band, with a duration of ~25 minutes.Comment: 10 pages, 3 figures, in press in ApJ
Mammalian Cell Cytotoxicity Analysis of Soybean Rust Fungicides
The identification of soybean rust, caused by Phakopsora
pachyrhizi H. Sydow & Sydow, in the southern United
States in November 2004 (Schneider et al. 2005 ), in the
Midwest in 2006 (Hartman et al. 2007 ), and elsewhere has
increased the concerns of the impact of the pathogen on US
soybean production (Miles et al. 2007 ). The rapid spread of
P. pachyrhizi and its potential to cause severe yield losses
makes this among the most destructive foliar diseases of
soybean. Yield losses of 20%â60% were reported in Asia,
with losses of 80% reported from experimental plots in
Taiwan (Hartman et al. 1991 ). Soybean rust could have a
major impact on both total soybean production and production
costs in the US
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